We have tried to 3D print the attached drawing for our waterjet nozzle, and some nozzles turned out to be fine but the problem is we cannot reproduce them because they are extremely tiny and also the shape is not a perfect cylinder. Does anybody know any machining method that we can do this or any place that can do this for us? Any help or suggestion is highly appreciated.
Thanks!
Step One - Produce Dome top Cylinder shape using CNC milling machine (3 Axis).
Step Two - Use wire EDM drilling process for creating the cavity. It can be easily done with a wire of 0.2 to 0.3 mm in diameter.
Abhishek Verma Thanks for your answer. I should check if we have edm drill in our machine shop. Thanks again!
I would agree with Abhishek and the use of EDM drilling. If you get problems with the depth of the 0.33mm hole, possibly drill right through the part with a smaller wire, drill the angled hole until they intersect, then EDM ream the 0.33 hole to give a smoother intersection. Finally, plug the 0.33mm hole to the required depth. The end of the plug can be contoured (prior to fitting) to give a rad at the intersection of the holes to give better flow characteristics.
Let me know how you get on.
Regards
Andrew
Andrew Barnett Thanks for the answer! The 3D printed parts are from PCL. the major problems with 3D printed parts are that i cannot reproduce the exact same nozzles, and that the friction is high even if using some oil at the tip. For your recommended EDM approach (I talked with the machine shop and they have this method) I will make a metal nozzle. Will update here how it goes soon.
You should conventionally micro-Drill the hole so that it is round. 0.2mm drill can be purchased on the open market. There is a bit of a knack to getting the RPM and feedrate right- the drill supplier can help with that. Drills make a much smoother and more cylindrical hole than EDM.
Example:
https://www.dormerpramet.com/en-us/pages/productsearchresults.aspx?q=micro%2Bdrill
In addition to the above given methods, laser cutting (drilling) can give you the most accurate diameter and smooth surface. Caveat - More precision and accuracy comes at an extra cost.
Laser cutting will not really work in this case because the holes intersect in the body of the component, as opposed to being through holes, which you could trepan out (a spiral cut from the centre outwards until a full circle is cut). You can form the holes via pulse drilling until you reach the required depths but the sides will be irregular.
Andrew Barnett I am still using the 3D printed part the EDM did not work since they could not drill a hole at 30 degrees.
U. Ashok Kumar Yatish Rane David Shea Thanks for your replies I will consider them.
Hi Mahdieh,
We have prototyped a version of the nozzle in metal via laser sintering, see attached photo. we have an angled hole in the part, we have yet to x-ray to see the internal profile. there is some deformation of the hole opening and the parts have not yet been cleaned up hence the metal spatter on the outside. I have had a thought of an alternative method, which if we can trial it I will let you know how we get on.
Andrew Barnett The main issue is that when waterjet goes through the hole, the wall thickness should be able to stand the pressure and does not spray water. Our main challenge is to get a focused jet (I can do that with 3D parts but they are not reproducible and every 3D-printed part has a different angle).
Andrew Barnett How much does prototyping with laser sintering cost?
Andrew Barnett Nozzle angle of 30 ish is a good angle. My current nozzle is 38 degrees.
Hi,
I've been told our holes are at the 134deg as per the drawing. Ours have been made in titanium so the walls should be strong enough providing the sintering density is sufficient. I can investigate the cost.
Andrew Barnett Yes you are right! We made a 45 angle and we got 38 degree :D Thanks for your reply and I would like to get an estimate of the cost too!
